Broadband Connection?

From your question, I do not know if you are referring to computer, a router, a wireless router, etc.

If a computer, install Eset Smart Security Suite and run a full scan.

If a wireless router,

Change the SSID from the default.

Set a new password for the admin account

Enable SPI if you have an option to.

Enable WPA or WPA2.

Use strong long passwords.

Enable MAC address filtering.

Limit the range for DHCP to a number you need.

Turn off the SSID broadcast after you are finished setting everything up.

Even if you follow and implement all of that your wireless router isn't intrusion proof, it just makes it a less likely target than the one down the street that is wide open.

What brand is the router? If you have a Linksys, go to 192.168.1.1 and the default user is admin and password is admin. There is a tab that says security and you will be able to set a passcode. My recommendation is WPA and make it something you can remember. If it is not a Linksys, send me a message with the brand router and I will help you further.